Experimental design for the optimization and modeling of the photoelimination of reactive red 120 from aqueous solution by supported TiO2 [Modélisation et optimisation de la photoélimination du rouge réactif 120 en milieu aqueux en présence de TiO2 supporté]

Experimental design was used to study the main effects and the interaction effects between operational parameters in the photoelimination of azo dye reactive red 120 (rr120). the important parameters which affect the removal efficiency of rr120 are the initial dye concentration,the amount of catalyst and the ph. the parameters have been respectively coded into x1,x2 and x3,and have been investigated between the two levels (-2 and +2). the results show that the application of response surface methodology (rsm) allows describing in a correct manner the influence of these three experimental parameters on the treatment efficacy. the optimal values of the parameters for the maximum performance were determined. the suggested second order model for the degradation efficiency was validated using different statistical approaches. the response surface 3d plots and the contour plots were used to locate the optimal point. the optimum conditions that were obtained for the photoelimination of the rr120 dye were as follows: the initial dye concentration: 20 mg/l,the amount of catalyst: 0.81 g and the ph of the solution: 5.